Our proposed research deals with environmental light damage to the retina of normal mice and rats and of those undergoing various forms of inherited retinal degeneration. Our goals are to clarify the cytopathologic steps in light damage due to fluorescent lighting, with particular emphasis on the involvement of the retinal pigment epithelium and eye pigmentation. We hope to define a genetic factor in susceptibility to light damage in otherwise normal retinas and to explore the role of the interphotoreceptor matrix in light damage. Our analysis of the influence of environmental lighting on several inherited retinal degenerations should offer useful guidelines on some aspects of the management of patients with retinitis pigmentosa.